This fic is so clever, very unique and just generally breath-taking. It's very in-depth, detailed, and it's clear that everything has been well thought-out, very much so. The only thing I can think of that could improve it relates to Nanako's chapter - as I recall, Konata in one episode mentions how Kuroi fell asleep at the keyboard in the middle of an MMO they were playing together. As such, perhaps you can mention that one exceptionally lucky magical girl managed to glance at the Witch, which happily dozing away, before they managed to escape?

It is said that adults cannot become Magical Girls. Incubators target only adolescent girls because they are the most likely to make a wish on the spot, whereas any adult will take time to think their wish through. For that reason, Nanako most likely cannot become a Magical Girl, and thus cannot become a Witch, although what you specified for her could just as easily be for Konata.

In case you intend to continue this at any point, I suppose Ayano could become a Caretaker Witch, Kagami could become a Snack Witch, and Miyuki become a Dentist Witch. Miyuki's Witch form could also have a familiar named Kirby, after the elf who wanted to become a dentist in Rudolph the Red-Nosed Reindeer.

I saw that this fic has so few reviews and thought it certainly deserves more. All of the ideas for the witches where great and very detailed, and quite dark in general, something I realy enjoyed in the orignal Pmmm. You should definately write on, I would like to see the remaining cast done.

Just for fun: in my headcanon, Kagami's Witch name is Sieglinde, for a number of complicated reasons, but the most important one being that it means "victory" in German, just like the name Vittoria does in Italian.